1) Field of the Invention
The present invention relates generally to agricultural implements and, more specifically, to a device for separating relatively heavy materials from a crop being conveyed through the air duct of a cotton harvester or similar implement.
2) Related Art
Harvesters such as cotton strippers include a conveying system with an air duct for moving material from stripping mechanisms upwardly and rearwardly toward a basket or cotton cleaner on the implement. The air stream carries green bolls and debris along with the desired cotton crop, and to remove some of the unwanted material, separators are typically incorporated into an area of the duct. Examples of such separators are shown in U.S. Pat. Nos. 4,606,177 and 5,394,679 assigned to Deere & Company. Heavy material such as rocks and green bolls tends to drop downwardly through an opening in the duct and out of the stream of material being conveyed to the basket or cleaner.
Although previously available separators have reduced the amount of trash reaching the basket or cleaner, a substantial amount of undesirable material often remains in the system. When a cleaner is employed on the implement, green bolls and debris foul the saws in the cleaner. Debris such as rocks and stumps can cause considerable damage to the internal components of the cleaner if they are not separated out properly. Increased trash content decreases the crop grade and results in a lower price for the crop. In high yield cotton, green bolls and debris often gets carried up with large clumps of cotton and therefore do not have an opportunity drop out of the material stream. In addition, the large clumps of material can cause blockages in the duct.
Clumping problems are increased as material directed rearwardly from the cross auger outlet is concentrated towards one side of the outlet and separation duct rather then being uniformly distributed across the width of the duct. Typically a pair of paddles offset 180 degrees from each other propel material rearwardly through the outlet. As the material is directed into the paddle area by the auger flighting, the initial contact between the paddles and the material typically directs excessive amounts of material rearwardly along the sides of the separation duct with less material near the center of the duct. Also, each paddle must move a relatively large amount of material from a full revolution of the associated auger flighting.